Watersport boards such as surfboards and stand-up paddleboards (SUPS) generally are configured to permit a user to stand upon an upper surface of the watersport board while the watersport board floats in a body of water. A watersport board may include at least one fin extending into the body of water from an underside of the watersport board to stabilize the watersport board and/or to provide the user with directional control as the watersport board traverses the body of water. A fin that is integrally formed with the watersport board or permanently coupled to the watersport board may be difficult to repair and/or replace in the event of damage, such as may result from a collision with a foreign object. Accordingly, a watersport board may include a fin box or other structure configured to selectively receive and retain the fin in an operative position on the watersport board. Conventional fin boxes and removable fins may require the use of tools to retain the fin within the fin box and/or to remove the fin from the fin box. Other conventional fin boxes and removable fins do not require the use of tools but may not sufficiently secure the fin in the fin box to prevent unintentional removal of the fin from the fin box during use of the watersport board. Thus, there exists a need for watersport board fins with fin retention systems.